The purposes of Phase II of this project are to: a) develop a series of three cooperative strategies that classroom teachers can teach to their heterogeneous classes (that include mainstream students with learning disabilities) as they work together in cooperative group structures in the regular classroom; and b) develop and empirically validate the materials and instructional procedures that are necessary for effectively and efficiently producing mastery of those strategies. This Phase II project is an extension of the Phase I research that clearly demonstrated that the social performance of students with disabilities could be significantly improved through the explicit instruction of targeted social skills and cooperative strategies. The new strategies, materials, and procedures will be developed with the help of two internationally recognized scholars in the fields of disability, social skills, and cooperative learning: Drs. David Johnson and Robert Slavin. Each program will be piloted and field-tested in mainstream classrooms. Students' cooperative skills will be measured before and after instruction using paper-and-pencil and cooperative group assignments. Instructional materials will be revised until student results and teacher satisfaction with the materials is at a sufficiently high level to warrant preparation for commercial distribution. PROPOSED COMMERCIAL APPLICATION: A major instructional strategy used in our nation's schools is cooperative learning structures. Unfortunately, there are not empirically validated materials that teachers can use to promote positive social interactions among heterogeneous groups (including those with learning disabilities). The materials produced by this grant will directly address this major instructional problem confronting classroom teachers.